1. Field of the Invention
The present invention relates to creating fog, which may be in the form of mist. More particularly, the invention relates to using fog or mist in a visually appealing display or as a conduit for drug delivery.
2. Description of the Related Art
There are generally four types of visual vapor or fog generators on the market today. Carbon dioxide (“CO2”) fog generators generate a visual fog using a solid block of CO2 (i.e., dry ice) which is dropped into a bath of deionized (“DI”) water heated to 140° F. or higher. One disadvantage of CO2 fog generators is that the fog quantity they produce is unregulated, i.e., the fog quantity cannot be readily applied in any situation without adjusting the size of the of CO2 block as the quantity of fog produced is largely based on the size of the block used. Further, in applications requiring a large amount of fog, the size of the CO2 fog generator can become large and cumbersome. In addition, as the CO2 block melts, the quantity of fog output from the fog generator diminishes and the temperature of the DI bath is lowered which, in time, will require a reheating of the water or adding more hot water thereto. Further, when the CO2 block melts, it must be replaced by another costly CO2 block.
Helium bubble generators, as the name implies, generate small helium filled bubbles of water that float in the air at almost neutral buoyancy. Unfortunately, helium bubble generators tend to produce a small quantity of bubbles that may fail to create a dense and realistic fog. Further, increasing the helium levels in a room may have a negative impact on the comfort of people in the room.
A third type of fog generator generates a fog by passing steam from boiling water through a bath of liquid nitrogen (“N2”) creating a super cooled fog. Similar to the CO2 block fog generator, liquid N2 fog generators tend to be large and require a continuous supply of costly of liquid N2. Further, these fog generators may be hazardous because they require both a boiler to heat the water and extremely cold liquid N2 to operate.
Finally, ultrasonic fog generators create fog by vibrating a bath of water using ultrasonic sound. The fog may be disbursed through a long hose in which water vapor fog may condense.
One common fact among the aforementioned fog generators is the creation of fog in a way that fails to be visually pleasing, i.e., the only thing created is fog. In addition, the fog created serves no purpose other than perhaps being indicative of airflow and simulating fog.